Nāpali Coast State Wilderness Park – This holiday weekend, fishermen from Kaua‘i’s west side and from the north shore joined forces with a team from the DLNR Division of Aquatic Resources (DAR) to try and remove invasive Black Chin Tilapia from Nu‘alolo Bay here.
Over the past few weeks, anglers have reported the presence of thousands of tilapia in the shallow waters of the bay and this was confirmed by the DAR team, who initially collected some fish for biological sampling. It is believed the Black Chin Tilapia was introduced into Hawai‘i as a bait fish back in 1962, though an alternate theory has them being introduced around the same time to control aquatic weeds. On O‘ahu it is the most common tilapia species and is also documented on Hawai‘i Island.
Using a combination of surround nets and throw nets under a State Special Activities Permit, more than a dozen fishermen and the DAR team, worked all day Saturday and into the night to try and remove as many of the wily fish as possible. Several volunteers commented, “they’re smart buggers.” As soon as they were trapped by a net many of the tilapia found openings and escaped. Ka‘ili Shayler of DAR led the weekend efforts, which included another full day of netting on Sunday, and said, “We removed about 300 tilapia. We tried different tactics and what seemed to work best was using throw nets at night during low-tide.” Previously, fishermen had removed an estimated 1000 fish on their own.
Tilapia reproduce fast and DAR biologists say this means they out-compete other species (including native fish), and then often suffer massive die-offs. They’re considered pests in estuaries, canals and reservoirs, and though tilapia is largely considered a fresh-water fish, the Black Chin is known